There is an image sensor using an organic photoelectric conversion film as a photoelectric conversion element (for example, see Patent Literature 1). Since the organic photoelectric conversion film can simultaneously perform color separation and light reception as a thin film, an aperture ratio is high and an on-chip lens is basically unnecessary.
There is also an image sensor in which a photodiode is also formed in a silicon layer below an organic photoelectric conversion film and phase difference detection is performed by the photodiode of the silicon layer while an image is acquired by the organic photoelectric conversion film (for example, see Patent Literature 2).